Mould growing on floorboard filler???

[Richard Burns]

Hi everyone, hope someone can help and hopefully I'm in the right chat.

Yesterday I filled the gaps in my parquet flooring with Wudcare floorboard gap and joint filler.
Today I've gone to sand it down and it appears to be mouldy.
Can anyone shed any light on this please?

 

[Cobbs]

Maybe you should contact the manufacturer.

 

[Dee J]

Is it old or new parquet? What was the subfloor like before filling? It seems a bit quick for mould, wondering if it's some some of glue, mastic or pitch subfloor coating that's tracking through as staining?

 

[Richard Burns]

I took some photos.

I have sanded all back down.

I spoke to the manufacturer and the chap on the phone suggested that mould spores can lay dormant in oak and possibly the water based filler has activated it.
Suggested I sand down and isolate the wood (not sure what that means tbh) and make sure I only use solvent based products.